While foodborne illnesses are rarely pleasant, certain types can hit pregnant people and newborns especially hard. According to food-poisoning expert Bill Marler, listeria should be a top concern for any expectant mother.

"Listeria illnesses in moms pass to the baby in uterus and can kill or damage the baby," Marler, who is an attorney specializing in foodborne-illness cases, told Business Insider.

More than 200 people died in a listeria outbreak stemming from a meat-production plant in Polokwane, South Africa, earlier this year. Newborns were the most likely to be impacted by the outbreak, with 91 babies under the age of 28 days old dying as a result of listeriosis.

To reduce the risk of foodborne illness, pregnant women should avoid eating certain foods, according to Marler. Here's what the food-poisoning expert says to cut from your diet, according to a list Marler wrote for Food Safety News and shared in conversations with Business Insider.

1/

Raw or undercooked meat

Shutterstock

Rare meat is one of a number of things that Marler himself doesn't eat and advises against pregnant women consuming. If meat isn't cooked to 160 degrees, he says, bacteria can thrive and cause E. coli or Salmonella poisoning.

Raw or undercooked eggs

Narong Jongsirikul/Shutterstock

Eggs and products such as homemade Caesar salad dressing, mayonnaise, ice cream, custards, and hollandaise sauce have the potential to carry salmonella. In April, the FDA announced a recall of 206 million eggs over salmonella-contamination concerns.

7/

Oysters, clams, and mussels

Melie Nasr / Shutterstock.com

Marler says he has seen more foodborne illnesses linked to shellfish in the past five years than in the two preceding decades.

According to Marler, global warming is heating up oceans and allowing microbial growth to thrive, which encourages the spread of foodborne illnesses like norovirus and vibrio infections.

8/

Smoked fish

Smoked seafood comes with listeria concerns, though canned and shelf-safe fish (such as tuna) is safe to eat. However, pregnant women and nursing mothers should avoid fish with high levels of mercury — not because of food-poisoning concerns, but because high mercury levels can harm brain development.

9/

Home-canned food

Stick to professionally canned jams while pregnant, Marler says. Home-canned goods can contain botulism, or be contaminated with other ways, as DIY canning operations don't have the same safety regulations as professional enterprises.

10/

Sprouts

Shutterstock

Because sprouts are grown in standing water, they are a prime spot for bacteria such as salmonella to thrive. Sprout-related outbreaks are common, with more than 30 bacterial outbreaks— primarily related to salmonella and E. coli — happening in the past two decades.